Ethylene for February was offered at 49.00 cents/lb, up from 45.50 cents/lb in the morning.

Meanwhile, bids for February rose to 46.50 cents/lb from 44.00 cents/lb. Ethylene traded at 44.25-46.00 cents/lb on Monday.

The fire at Enterprise was forcing some crackers to run at reduced rates because of constraints on ethane supply, a market participant said.

The fire erupted at about 12:30 hours Houston time following explosions at the facility, which were still continuing on Tuesday afternoon, local news reports said.

An official with the Mont Belvieu Police Department said that no orders for evacuation or shelter-in-place had been issued, adding that the department was unaware of any injuries.

However, market sources said one contractor was still unaccounted for as of 13:30 hours Houston time (19:30 GMT).

Enterprise Products confirmed that report, according to Houston CBS television affiliate KHOU. The station also said witnesses reported seeing workers fleeing from the plant.

Meanwhile, other workers were being told to stay inside, KHOU reported.

Enterprise Products did not respond to requests for further comment about the status of the complex, which is the largest underground storage facility for NGLs in the world.

Market sources said the explosions and subsequent fire occurred in an iso-octane unit on the west side of the complex, near several storage facilities. Those also are near a liquefied petroleum gas (LPG) pipeline.

The storage facilities, which Enterprise acquired in 2001, consist of 30 salt-dome caverns with a total capacity of 77m bbl, according to the company’s website.